Disk recording or playback device having a retractable tray with a positioning mechanism for preventing a slider from inadvertently moving laterally

ABSTRACT

A positioning mechanism for preventing a slider from inadvertently moving laterally comprises a projecting wall provided on a lower surface of a tray and having a first wall extending forward and a second wall extending from the first wall toward a direction orthogonal to the first wall, and at least two projections provided on the slider for holding therebetween the second wall when the tray is in a completely advanced state and the first wall when the tray is in an advancing or a retracting state.

TECHNICAL FIELD

The present invention relates to disk recording or playback deviceshaving a retractable tray for placing a disk thereon.

BACKGROUND ART

FIG. 10 is a perspective view of a conventional disk recording orplayback device having a tray, and FIG. 11 is a plan view of aconventional chassis 1. The device is a CD (compact disk) player. In thefollowing description, the direction in which the disk is drawn onto achassis 1 will be referred to as “forward,” and the direction in whichthe disk is ejected from the chassis 1 as “rearward.”

Provided on the chassis 1 are a mechanism deck 5 for reproducing signalsfrom a disk D, a slider 3 coupled to the deck 5 and movable laterally,and a drive gear 10 coupled to a motor (not shown). Provided over themechanism deck 5 and the slider 3 is a tray 4 for placing the disk Dthereon. The tray 4 is movable forward and rearward by meshingengagement with the drive gear 10. As is already known, the tray 5 has alarge recessed surface 44 for placing a large disk thereon and a smallrecessed surface 45 for placing a small disk thereon.

The disk D is held between a clamp 8 disposed above the tray 4 on thechassis 1 and a turntable 51 for rotating the disk.

With reference to FIG. 11, the mechanism deck 5 comprises, as mounted ona base 50, the turntable 51 and a pickup 52 movable toward or away fromthe turntable 51 and having an objective lens 53 for projecting a beamon the rear surface of the disk D. The pickup 52 moves along guide rods54, 54 provided on the upper surface of the base 50. The beam from thepickup 52 impinges on the disk rear surface through an opening 40 formedin the tray 4. The base 50 is movable upward or downward as supported bya pivot 56 on the chassis 1.

The slider 3 has a pin 39 projecting from its upper surface and fittingin the tray 4. As shown in FIG. 12, the slider 3 is provided at itsfront end with a vertical plate 31. A cam follower 55 projecting fromthe base 50 is fitted in a cam slot 36 formed in the vertical plate 31.

FIG. 13 is a rear side view of the tray 4. The rear side of the tray 4is provide with a rack 41 meshing with the drive gear 10 and a guidegroove 49. The pin 39 on the slider 3 is fitted in the guide groove 49and is restrained from inadvertently shifting laterally relative to thetray 4. The guide groove 49 has a straight portion 49 a extendingrearward, and an inclined portion 49 b extending from the rear end ofthe straight portion 49 a.

FIGS. 15A and 15B are views in section taken along a plane containingthe line D—D in FIG. 10. In the state shown in FIG. 15A wherein the tray4 is completely retracted, the mechanism deck 5 has its rear end moveddown about the pivot 56. The tray 4 is advanced from this state by therotation of the drive gear 10. When the pin 39 is fitted into theinclined portion 49 b of the guide groove 49 of the tray 4 from thestate shown in FIG. 14, the slider 3 moves leftward with the advance ofthe tray 4. With the mechanism deck 5 fitting in the cam slot 36 of theslider 3, the mechanism deck 5 is raised to a horizontal position by themovement of the slider 3 as shown in FIG. 15B. The disk D is clampedbetween the turntable 51 and the clamp 8.

To be satisfactory, the opening 40 of the tray 4 in the conventionaldevice is so sized as to permit the beam from the pickup 52 to passtherethrough. In recent years, however, it is desired that diskrecording or playback devices of the type described be reduced inthickness, so that there arises a need to reduce the spacing between thepickup 52 and the tray 4. Consequently, the opening 40 must be enlargedwithout permitting the guide rods 54 to be positioned below the opening.This entails the objectionable result that no space is available forproviding the guide groove 49.

Further for use with DVDs (digital versatile disks) which are higherthan CDs in signal recording density, devices are available wherein anobjective lens for projecting a CD playback beam and an objective lensfor projecting a DVD playback beam are arranged side by side. Thisarrangement provides an increased spacing between the pickup 52 and theguide rods 54, 54. Accordingly, the tray 4 needs to have an enlargedopening 40 so as to fulfill the need to clear the pickup 52 and theguide rods 54, 54. This leads to the drawback that no space is availablefor providing the guide groove 49. Without the guide groove 49, theconventional construction would permit the slider 3 to move laterallyinadvertently and involve variations in the height of the mechanism deck5.

An object of the present invention is to restrain the slider from movinglaterally inadvertently even if the tray has an enlarged opening.

DISCLOSURE OF THE INVENTION

A positioning mechanism for preventing a slider 3 from inadvertentlymoving laterally comprises a projecting wall 7 provided on a lowersurface of a tray 4 and having a first wall 70 extending forward and asecond wall 71 extending from the first wall 70 toward a directionorthogonal to the first wall 70, and at least two projections 32, 33provided on the slider 3 for holding therebetween the second wall 71when the tray 4 is in a completely advanced state and the first wall 70when the tray 4 is in an advancing or a retracting state.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a device with a tray in a completelyadvanced position;

FIG. 2 is a perspective view of the device with the tray omitted;

FIG. 3 is a perspective view of the device with the tray in a completelyretracted position;

FIG. 4 is a perspective view of a slider;

FIG. 5 is a perspective view of the tray as it is seen from below;

FIG. 6 is a plan view of the tray as completely advanced;

FIG. 7 is a plan view showing the tray in a retracting movement from thecompletely advanced position;

FIG. 8 is a plan view showing the tray in the retracting movement;

FIG. 9 is a plan view showing the tray in the retracting movement;

FIG. 10 is a perspective view of a disk recording or playback devicehaving a tray and previously proposed by the present applicant;

FIG. 11 is a plan view of a conventional chassis;

FIG. 12 is a view of a slider shown in FIG. 11 and as viewed from thedirection C;

FIG. 13 is a rear side view of the tray;

FIG. 14 is a plan view showing the tray as fitted to the slider; and

FIGS. 15A and 15B are views in section taken along a plane containingthe line D—D in FIG. 10.

BEST MODE OF CARRYING OUT THE INVENTION

An embodiment of the invention will be described below in detail withreference to the drawings concerned.

FIG. 1 is a perspective view of a device with a tray 4 in a completelyadvanced position, and FIG. 2 is a perspective view of the device withthe tray 4 omitted. FIG. 3 is a perspective view of the device with thetray 4 in a completely retracted position, the view not showing theclamp 8 to be described below. As in the prior art, a mechanism deck 5has a turntable 51 and a pickup 52 and is movable upward and downwardabout a pivot 56 on a chassis 1 (see FIG. 11). Provided above thechassis 1 is a clamp support plate 11 positioned above the tray 4 andintegral with the chassis 1. The clamp 8 for holding a disk between theturntable 51 and the clamp 8 is provided on the support plate 11 and ismovable upward and downward by a very small amount relative to the plate11. The clamp 8 has a known construction and will not be described indetail.

With reference to FIG. 2, the chassis 1 has mounted thereon a drive gear10 rotatable by a motor M by way of an intermediate pulley 12 and a belt13. The drive gear 10 is in mesh with the tray 4 as will be describedbelow.

Each side wall of the chassis 1 is provided with upper support pieces42, 42 and lower support pieces 43, 43, and the tray is disposed betweenthe upper support pieces 42, 42 and the lower support pieces 43, 43. Aslider 3 is laterally movably provided on the chassis 1. Upwardlyprojecting from the slider 3 are two first projections 32, 32 which areaway from each other and a second projection 33.

FIG. 4 is a perspective view of the slider 3. The slider 3 comprises ahorizontal plate 30, and a vertical plate 31 extending downward from thefront end of the plate 30. One of the first projections 32 and thesecond projection 33 are spaced apart on the horizontal plate 30 by aclearance H laterally of the device and by a clearance G forwardly orrearwardly thereof. As will be described later, a projecting wall 7 ofthe tray 4 fits in the clearance H or G. The second projection 33 isflat on the front side and rear side thereof, while both the projections32, 33 may be made flat on the front side and rear side thereof.

The horizontal plate 30 has a rack 34 in mesh with the drive gear 10.Two switch pushing lugs 35, 35 which are away from each other areprovided below the rack 34. These lugs 35, 35 are positioned under thechassis 1 for pushing a sensor switch SW (see FIG. 2) attached to thelower side of the chassis 1.

The vertical plate 31 has cam slots 36, 36 for respective cam followers55, 55 (see FIG. 11) on a base 50 to fit in. When the slider 3 moveslaterally, the mechanism deck 5 fitting in the cam slots 36, 36 movesupward or downward. Only one cam slot 36 or at least two cam slots 36may be provided.

FIG. 5 is a perspective view of the tray 4 as it is seen from below. Thetray 4 has a larger opening 40 than conventionally, and the pickup 52and guide rods 54 (see FIG. 11) are fittable thereinto. The tray 4 hastwo projecting walls 7, 7 at respective side portions thereof. One ofthe projecting walls 7 has a first wall 70 extending forward, a slantingwall 72 extending from the rear end of the first wall 70 and slantingrearwardly inward, and a second wall 71 extending from the rear end ofthe slanting wall 72 toward a direction orthogonal to the first wall 70.The end of the second wall 71 opposite to the slanting wall 72 is closedwith a cover wall 73 joined to the second wall 71. The first wall 70 hasa front end portion which comprises a cam wall 74 slanting outward and athird wall 75 extending from the front end of the cam wall 74 andgenerally parallel to the first wall 70. The other projecting wall 7comprises a second wall 71 and a cover wall 73 and has an open innerend. Provided on the rear side of the tray 4 outwardly of the first wall70 of the first-mentioned projecting wall 7 is a rack 41 extendingforward to mesh with the drive gear 10.

With the tray 4 in a completely advanced position, signals can berecorded on or reproduced from a disk. As in the prior art and as shownin FIG. 15B, the mechanism deck 5 is moved upward to a horizontalposition by the movement of the slider 3, the turntable 51 raises thedisk D, and the clamp 8 and the turntable 51 clamp the disk Dtherebetween. Through the opening 40 of the tray 4, a beam is projectedonto the rear surface of the disk from pickup 52.

[Retraction of the Tray]

The tray 4 is retracted from the completely advanced position in themanner to be described below with reference to the plan views of FIGS. 6to 9. For the convenience of illustration, the mechanism deck 5 is notshown in FIGS. 6 to 9. In the state shown in FIG. 6 wherein the tray 4is completely advanced, the second wall 71 fits in the clearance Gbetween the left first projection 32 on the slider 3 and the secondprojection 33 thereon. In the state of the tray 4 as completelyadvanced, the second wall 71 is held between the first and secondprojections 32, 33, and the first projection 32 is held in a groovedefined by the second wall 71 and wall 73 a, so that even if the deviceis subjected to an impact as by falling, the load of impact is receivedby the two projections 32, 33 and the walls 71, 73 a. Thus, the impactload is dividedly received by the two projections 32, 33 and the twowalls 71, 73 a. This reduces the likelihood of the projections 32, 33breaking. Especially, the portion of the second projection 33 in contactwith the second wall 71 has a flat face, so that the load per unit areais small, further diminishing the likelihood of the second projection 33breaking.

The left switch pushing lug 35 pushes the sensor switch SW (see FIG. 2),whereby the tray 4 as brought to the completely advanced position isdetected. The rack 34 of the slider 3 meshes with the drive gear 10,while the rack 41 of the tray 4 is out of meshing engagement with thedrive gear 10.

The drive gear 10 rotates counterclockwise with the tray 4 in itscompletely advanced position. The slider 3 moves leftward, the rightsecond projection 32 leaves the second wall 71, and the left firstprojection 32 comes into contact with the slanting wall 72 as shown inFIG. 7. This first projection 32 pushes the tray 4 rearward, meshing therack 41 of the tray 41 with the drive gear 10.

The drive gear 10 further rotates, retracting the tray 4 furtherrearward and causing the first projection 32 to move the slider 3leftward by contact with the slanting wall 72 as shown in FIG. 8. Therack 34 of the slider 3 is disengaged from the drive gear 10 totemporarily halt the slider 3.

When the drive gear 10 further rotates, the tray 4 is further retracted.The tray 4 is retracted with the first wall 70 fitting in the clearanceH between the first projection 32 and the second projection 33 as shownin FIG. 9. This prevents the slider 3 from moving leftward or rightwardinadvertently.

Upon the two projections 32, 33 reaching the cam wall 74 and the thirdwall 75, the slider 3 moves outward again. The right switch pushing lug35 pushes the sensor switch SW, whereby the tray 4 as brought to acompletely retracted position is detected. The drive gear 10 is broughtout of rotation. When the tray 4 advances, a movement reverse to theabove is conducted, so that the advance movement will not be describedin detail.

The slider 3 is positioned in place by the slider projections 32, 33holding the first wall 70 of the tray 4 therebetween. Although the tray4 has the guide groove 49 for positioning the slider 3 in place withrespect to the lateral direction in the prior art, the first wall 70 isprovided on the tray 4 according to the present invention, so that thearea to be occupied by the component of the positioning mechanism to beprovided on the tray 4 for the slider 3 can be smaller. Accordingly, theslider 3 can be positioned in place with respect to the lateraldirection although the opening 40 has an increased size.

INDUSTRIAL APPLICABILITY

With the tray 4 in its completely advanced position, the projections 32,33 on the slider 3 hold the first wall 70 of the tray 4 therebetween,whereby the slider 3 is positioned in place with respect to the lateraldirection. Although the tray 4 of the prior art has a guide groove 49for positioning the slider 3 in place, the tray 4 of the invention hasthe first wall 70. This reduces the space to be occupied by thecomponent of the positioning mechanism provided on the tray forpositioning the slider 3. The slider 3 can therefore be positioned inplace although the tray has a large opening 40.

Further with the conventional device, a single pin 39 is fitted in theguide groove 49 for positioning the slider 3 in place, whereas when thedevice is subjected to an impact as by falling with the tray in itscompletely advanced position, the entire load of impact is applied tothe single pin 39 to possibly break the pin 39. According to theinvention, the two projections 32, 33 hold the second wall 71therebetween with the tray 4 in its completely advanced position, sothat even if the device is subjected to an impact as by falling, theimpact is received by the two projections 32, 33 and the two walls 71,73 a. Thus, the impact load is dividedly received by the two projections32, 33 and the two walls 71, 73 a unlike the prior art. This reduces thelikelihood of the projections 32, 33 and the walls 71, 73 a breaking.

1. A disk recording or playback device having as provided on a chassis atray movable forward and rearward for placing a disk D thereon, a slidermovable as coupled to the tray, and a mechanism deck comprising aturntable for rotating the disk D and movable upward and downward ascoupled to the slider, a positioning mechanism being provided betweenthe tray and the slider for preventing the slider from inadvertentlymoving laterally, the disk recording or playback device beingcharacterized in that the positioning mechanism comprises a projectingwall provided on a lower surface of the tray and having a first wallextending forward and a second wall extending from the first wall towarda direction orthogonal to the first wall, and at least two projectionsprovided on the slider, the two projections being spaced apart byclearance H laterally of the device and by clearance G forwardly orrearwardly of the device, the second wall fits in the clearance G whenthe tray is in a completely advanced state, and the first wall fitsclearance H when the tray is in an advancing or a retracting state.
 2. Adisk recording or playback device according to claim 1 wherein at leastone of the projections is flat at a portion thereof to be brought intocontact with the second wall.